John MacFarlane has published a lengthy retrospective to commemorate twenty years of the Pandoc document converter. On August 3, 2006, I uploaded the first version of pandoc to my website, releasing it under the free GPL license. Pandoc 0.1 consisted of about 3000 lines of Haskell code, with no dependencies aside from GHC's standard library. It could convert Markdown, reStructuredText, HTML, and LaTeX documents into any of these formats, plus RTF or S5. I had no idea at the time that this would just be the first of over two hundred releases over the next twenty years; that the project would become the most popular program written in Haskell; that I would spend countless hours on bug-fixes, improvement, and project management; that I would collaborate with programmers in many other countries; that pandoc would come to support over fifty document formats; that it would allow automatic generation of citations and bibliographies; that it would become integrated into academic writing tools